Rotary paint chipper



April 1968 B. H. COMSTOCK 3,380,094

ROTARY PAINT CHI PPER Filed Sept. 30, 1965 2 Sheets-Sheet 1 v INVENTOR. B u. L. H. CoMs'rOcK ATTORNEY April 30, 1968 B. H. COMSTOCK 3,380,094

ROTARY PA INT CHI PPER Filed Sept. 30, 1965 2 Sheets-Sheet 2 m 0 m 'm -l INVENTOR. Bu. 1. H. COMSTOCK ATTORNEY United States Patent 3,380,094 ROTARY PAINT CHIPPER Bill H. Comstock, 260 La Cruz Ave., Millbrae, Calif. 94030 Filed Sept. 30, 1965, Ser. No. 491,726 2 Claims. (Cl. -93) ABSTRACT OF THE DISCLOSURE A rotary paint chipper having a power driven mandrel to which inner links of a plurality of chains are anchored, each chain providing an outer link having a striker swingably secured thereto, and each striker being defined by a staple having legs crossing one another so as to preclude accidental disengagement of the staple from its outer link, the ends of the legs beyond the crossing thereof being pointed and spaced from one another and facing outwardly to contact with a surface to be cleaned.

There are several known methods of removing paint from stucco and rough masonry surfaces, the disadvantages of which are briefly set forth as follows:

(a) The use of sand-blasting is an effective method of removing old paint from these and other surfaces; however, due to the expensive equipment involved, the inability to control the dust, and the probability of damage to adjacent surfaces such as windows, shrubs, etc., its use is beyond the scope of the normal home-owner or house painting contractor.

(b) Rotary scrapers are effective when used on a relatively smooth surface; but on a rough surface, the surface itself must be smoothed in order to reach all the old paint. This action has a tendency to alter the surface texture and to generally reduce the thickness of the stucco. Hand-scrapers tend to produce the same effect to a lesser degree and are ineflicient if the cost of labor is to be considered.

(c) Wire brushing has the effect of cleaning the surface of the very loose particles, but has a tendency to polish the old paint rather than to remove it.

(d) Sanding is only effective if the surface is relatively smooth and will further alter the surface texture by its inherent smoothing action.

(e) Chipping hammers do remove the old paint effectively by chipping the loose paint away from the surface. This striking power of the hammer must be rigidly controlled to prevent damage to the stucco surface and the hammer point must be small enough in size to enter the indentations of the surface to be effective in removing the old paint.

As the cardinal object of this invention, it is proposed to provide a rotary paint chipper that will overcome the foregoing disadvantages and which may be utilized to facilitate the removal of undesirable paint from stucco and rough masonry surfaces. In preparing exterior stucco walls for repainting, this paint chipper has been devised to remove the old paint from the rough surface without altering the original surface texture of the stucco.

Drawings For a better understanding of the invention, reference should be had to the accompanying drawings, forming part of this specification, in which:

FIG. 1 is a tranverse sectional view of my paint chipper this view being taken along the plane 11 of FIG. 2; and

FIG, 2 is a longitudinal sectional view taken along the horizontal plane 2-2 of FIG. 1.

While I have shown only the preferred embodiment of my invention, it should be understood that various changes, or modifications, may be made within the scope of the appended claims without departing from the spirit thereof.

Detailed description Referring now to the drawings in detail, I have shown a power driven mandrel A adapted to be rotated about its axis by any suitable means, for instance, a portable electric drill motor B having a chuck 10 to which a shank 11 of the mandrel may be secured.

It will be noted that a plurality of flexible chains C are provided, each having an inner link 12 anchored to the mandrel, such as by cotter pins 13 that pass through holes 14 formed at intervals along the length of the mandrel. Each chain further has an outer link 15, and the chains are swingable into substantially radial positions relative to the mandrel when the latter is rotated.

Moreover, a striker D is secured to the outer link 15 of each chain C, and each striker has at least one exposed outer chipping end 16 disposed for being brought into contact with a surface E to be cleaned of paint 17, dirt and other foreign matter during rotation of the mandrel.

The strikers D are swingably secured to their respective outer links 15 so that they may swing as they strike the surface to be cleaned, thus overcoming tendency of the strikers to break due to the impact. As clearly shown in the drawings, each striker defines a pair of pointed chipping ends 16 that face outwardly. Each striker D may be provided by a U-shaped staple, the curved portion 18 of the staple extending freely through an opening 19 in the outer link 15 of the chain to which it is secured, The legs 20 of each staple cross one another so as to preclude accidental disengagement of the staple from its link, and the pointed ends 16 of each staple are spaced r from one another in a direction extending longitudinally relative to the elongated mandrel A so as to cover a wider area of chipping (see FIG. 2).

For the purpose of protecting the operator against injury in the event that a chain C or striker D should break, and also protect the strikers from injuring the operator during rotation of the mandrel A, I have provided a protective shield F. As disclosed in FIG. 1, this shield is mounted around the mandrel A to enclose the chains C and their strikers D when they occupy positions on one side of the mandrel, the shield being open, as at 21, on the opposite side of the mandrel with the chains having sufficient lengths and the opening 21 being placed so that the strikers will project therethrough to positions therebeyond during rotation of the mandrel, as shown in FIG. 1 of the drawings.

The shield F is supported by the mandrel A and has a handle G that may be grasped by the operator to steady and guide the shield. Moreover, the shield has end plates 22 and 23 in which the mandrel is supported, and further defines a cylindrical wall portion 24 that is curved about the axis of the mandrel as its center of curvature. The handle G may have its straps 25 attached to the shield by rivets 26, welding or other suitable fastening means. The operator may grasp the drill B in the other hand.

As illustrated in FIG. 2, the mandrel A has journals 27 near its opposite ends that are rotatably mounted in bearings 28, for instance, made of Teflon. One of these bearings is carried by the end wall 22 and the other may be carried by a disc 29 that is secured by screws 30 to the other end plate 23, the latter having a large opening 31 formed therein through which the mandrel A may be inserted when assembling the paint chipper, and this opening is covered by the disc 29. Washer 32 and spring clip 33 hold the mandrel in place.

The strikers D are brought into contact with the surface to be cleaned of old paint, dirt, etc., and have the effect of many small chipping hammers striking many thousand times per minute. The resulting action upon the surface causes all paint or particles not securely adhering to the surface to be removed. The amount of weight of the strikers determines the force of impact for a given rpm. and flexible linkage length; this varying the size or weight of the strikers for a given paint blaster the depth of penetration and force exerted upon the surface can be controlled,

It is believed that this invention has a wide range of application. When constructed as shown in the drawings, it will be an inexpensive accessory to the popular electric hand drill B and invaluable to the home-owner who has stucco or masonry to repaint.

The contractor house painters use of the paint blaster could conceivably result in a better paint job at less cost because of the ease and speed of the surface preparation.

It is also believed that application could be extended to use in removing paint and rust from heavy metal surfaces as aboard ship where sand-blasting may be prohibitive. In this application the required impact force may necessitate use of heavier strikers than those used on the model applicable for stucco.

Advantages of the invention:

(a) Does a more thorough job of removing old paint.

(b) Does not cause dust contamination of surrounding area.

(c) Does not alter the surface texture of the stucco.

(d) It is easier (less physical exertion) to use than any other method known.

(e) Does not require large quantities of expendable material as in sand-blasting. Only occasional replacement of the strikers is anticipated.

(f) Easier to control than any other except hand scrapers or wire brushes.

(g) Faster than any known method except sandblasting if the extra work of masking and clean-up of sand, setting up of hopper, and starting compressor is neglected.

(h) Least expensive of all methods if time/labor are considered.

The interior of the shield F may serve as a hopper for collecting chipped particles of paint during the operation of the paint blaster, and these particles may be emptied from time to time.

I claim:

1. In a rotary paint chipper:

(a) an elongated power driven mandrel made to be rotated about its longitudinal axis;

(b) a plurality of flexible chains, each having an inner link anchored to the mandrel, and each chain further having an outer link formed with an opening therein, and the chains being swingable into substantially radial positions relative to the mandrel when the latter is rotated;

(c) and a striker secured to the outer link of each chain so that it may swing as it strikes a surface to be cleaned, thus overcoming tendency of the striker to break due to the impact, and each striker being defined by a staple having a pair of legs and a curved portion interconnecting these legs;

(d) the curved portion of each staple extending freely through the opening in the outer link of the chain to which it is secured, the legs of each staple crossing one another inwardly from their outer ends so as to preclude accidental disengagement of the staple from its outer link, and the ends of the legs beyond the crossing thereof being pointed and spaced from each other to provide a pair of pointed ends on each staple, the pointed ends of the legs facing outwardly and being exposed for being brought into contact with a surface to be cleaned of paint, dirt and other foreign matter during rotation of the mandrel.

2. The rotary paint chipper, as set forth in claim 1:

(e) and in which the pointed ends of the legs of each staple are spaced from one another in direction extending longitudinally relative to the elongated mandrel so as to cover a wider area of chipping.

References Cited UNITED STATES PATENTS 1,580,821 4/1926 Gevaerts 15-93 X 2,254,677 9/1941 Festini 15-179 3,082,452 3/1963 Heine et al. 15-236 X CHARLES A. WILLMUTH, Primary Examiner.

L. G. MACHLIN, Assistant Examiner. 

